Zero was first launched by the Hollywood Brands candy company of Minneapolis, Minnesota, in 1920 as the Double Zero Bar.

The coating melted at a higher temperature than brown chocolates, which made the bar a popular choice for summer vending in the pre-air conditioning South.

Hollywood Brands was first sold to Consolidated Foods Corporation in 1967 (which later became Sara Lee) and production continued after a fire destroyed the Centralia plant in 1980.

A new production facility opened in 1983, and in 1988 Hollywood Brands was purchased by Huhtamaki Oyj of Helsinki, Finland, and became part of Leaf, Inc.[2] Hershey Foods Corporation took over Leaf North America confectionery operations in 1996, and with it came the production of the Zero candy bar.

Finally, the candy is sold in a pack of 6 containing individually wrapped bars coming in at 1.85 ounces (52 g).